+/* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
+ * vim:expandtab:shiftwidth=8:tabstop=8:
+ *
+ * Copyright (c) 2002, 2003, 2004 Cluster File Systems, Inc.
+ * Author: Peter Braam <braam@clusterfs.com>
+ * Author: Phil Schwan <phil@clusterfs.com>
+ *
+ * This file is part of Lustre, http://www.lustre.org.
+ *
+ * Lustre is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * Lustre is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Lustre; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#define DEBUG_SUBSYSTEM S_LDLM
+#ifndef __KERNEL__
+# include <liblustre.h>
+#endif
+
+#include <linux/lustre_dlm.h>
+#include <linux/obd_support.h>
+#include <linux/lustre_lib.h>
+
+#include "ldlm_internal.h"
+
+/* Determine if the lock is compatible with all locks on the queue. */
+static int
+ldlm_inodebits_compat_queue(struct list_head *queue, struct ldlm_lock *req,
+ int send_cbs)
+{
+ struct list_head *tmp;
+ struct ldlm_lock *lock;
+ ldlm_mode_t req_mode = req->l_req_mode;
+ __u64 req_bits = req->l_policy_data.l_inodebits.bits;
+ int compat = 1;
+ ENTRY;
+
+ LASSERT(req_bits); /* There is no sence in lock with no bits set,
+ I think. Also such a lock would be compatible
+ with any other bit lock */
+ list_for_each(tmp, queue) {
+ lock = list_entry(tmp, struct ldlm_lock, l_res_link);
+
+ if (req == lock)
+ RETURN(compat);
+
+ /* locks are compatible, bits don't matter */
+ if (lockmode_compat(lock->l_req_mode, req_mode))
+ continue;
+
+ /* if bits don't overlap skip it */
+ if (!(lock->l_policy_data.l_inodebits.bits & req_bits))
+ continue;
+
+ if (!send_cbs)
+ RETURN(0);
+
+ compat = 0;
+ if (lock->l_blocking_ast)
+ ldlm_add_ast_work_item(lock, req, NULL, 0);
+ }
+
+ RETURN(compat);
+}
+
+/* If first_enq is 0 (ie, called from ldlm_reprocess_queue):
+ * - blocking ASTs have already been sent
+ * - the caller has already initialized req->lr_tmp
+ * - must call this function with the ns lock held
+ *
+ * If first_enq is 1 (ie, called from ldlm_lock_enqueue):
+ * - blocking ASTs have not been sent
+ * - the caller has NOT initialized req->lr_tmp, so we must
+ * - must call this function with the ns lock held once */
+int ldlm_process_inodebits_lock(struct ldlm_lock *lock, int *flags,
+ int first_enq, ldlm_error_t *err)
+{
+ struct ldlm_resource *res = lock->l_resource;
+ struct list_head rpc_list = LIST_HEAD_INIT(rpc_list);
+ int rc;
+ ENTRY;
+
+ LASSERT(list_empty(&res->lr_converting));
+
+ if (!first_enq) {
+ LASSERT(res->lr_tmp != NULL);
+ rc = ldlm_inodebits_compat_queue(&res->lr_granted, lock, 0);
+ if (!rc)
+ RETURN(LDLM_ITER_STOP);
+ rc = ldlm_inodebits_compat_queue(&res->lr_waiting, lock, 0);
+ if (!rc)
+ RETURN(LDLM_ITER_STOP);
+
+ ldlm_resource_unlink_lock(lock);
+ ldlm_grant_lock(lock, NULL, 0, 1);
+ RETURN(LDLM_ITER_CONTINUE);
+ }
+
+ restart:
+ LASSERT(res->lr_tmp == NULL);
+ res->lr_tmp = &rpc_list;
+ rc = ldlm_inodebits_compat_queue(&res->lr_granted, lock, 1);
+ rc += ldlm_inodebits_compat_queue(&res->lr_waiting, lock, 1);
+ res->lr_tmp = NULL;
+
+ if (rc != 2) {
+ /* If either of the compat_queue()s returned 0, then we
+ * have ASTs to send and must go onto the waiting list.
+ *
+ * bug 2322: we used to unlink and re-add here, which was a
+ * terrible folly -- if we goto restart, we could get
+ * re-ordered! Causes deadlock, because ASTs aren't sent! */
+ if (list_empty(&lock->l_res_link))
+ ldlm_resource_add_lock(res, &res->lr_waiting, lock);
+ l_unlock(&res->lr_namespace->ns_lock);
+ rc = ldlm_run_ast_work(res->lr_namespace, &rpc_list);
+ l_lock(&res->lr_namespace->ns_lock);
+ if (rc == -ERESTART)
+ GOTO(restart, -ERESTART);
+ *flags |= LDLM_FL_BLOCK_GRANTED;
+ } else {
+ ldlm_resource_unlink_lock(lock);
+ ldlm_grant_lock(lock, NULL, 0, 0);
+ }
+ RETURN(0);
+}